The maximum kinetic energy of photoelectron emitted from the surface of work function f due to incidence of light of frequency n is E. If the frequency of incident light is doubled, then maximum kinetic of emitted photon will be

1.  2E

2.  2E - f

3.  2E + f

4.  2E + 2f

Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V. The threshold frequency of the material is:

1. $4\times {10}^{15}Hz$                               

2. $5\times {10}^{15}Hz$

3.$\mathrm{<mspace\; width="1em"></mspace>1}.6\times {10}^{15}Hz$                           

4. $2.5\times {10}^{15}Hz$

The energy of a photon is E = hv and the momentum of photon $\mathrm{p}=\frac{\mathrm{h}}{\mathrm{\lambda }}$, then the velocity of photon will be

(1) E/p                     

(2) Ep

(3)  ${\left(\frac{\mathrm{E}}{\mathrm{P}}\right)}^2$                 

(4) $3\times {10}^8<mspace\; width="1em"></mspace>\mathrm{m}/\mathrm{s}$

Einstein's photoelectric equation states that \(E_k=h \nu -\phi.\)${\mathrm{}}_{}$ In this equation \(E_k\) refers to:

Einstein got Nobel prize on which of the following works

(1) Mass-energy relation

(2) Special theory of relativity

(3) Photoelectric equation

(4) (a) and (b) both